package com.file;

import com.utils.FileUtil;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;

@WebServlet(name = "UploadFile", urlPatterns = {"/UploadFile"})
public class UploadFile extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("application/json;charset=utf-8");
        // 检测是否为多文件上传
        if (!ServletFileUpload.isMultipartContent(req)) {
            // 如果不是则停止
            PrintWriter writer = resp.getWriter();
            writer.println("{\"msg\": \"Error: 表单必须包含 enctype=multipart/form-data\"}");
            writer.flush();
            return;
        }
        // 配置上传参数
        DiskFileItemFactory factory = new DiskFileItemFactory();
        // 设置内存临界值 - 超过后将产生临时文件并存储于临时目录中
        factory.setSizeThreshold(1024 * 1024 * 40); // 40MB
        // 设置临时存储目录
        factory.setRepository(new File(System.getProperty("java.io.tmpdir")));
        ServletFileUpload upload = new ServletFileUpload(factory);
        // 设置最大文件上传值
        upload.setFileSizeMax(1024 * 1024 * 40); // 40MB
        // 设置最大请求值 (包含文件和表单数据)
        upload.setSizeMax(1024 * 1024 * 50);  //50MB
        // 中文处理
        upload.setHeaderEncoding("UTF-8");
        // 文件存储路径路径
        String uploadPath = FileUtil.BASE_PATH;
        File uploadDir = new File(uploadPath);
        if (!uploadDir.exists()) {
            uploadDir.mkdir();
        }
        try {
            // 解析请求的内容提取文件数据
            List<FileItem> formItems = upload.parseRequest(req);
            if (formItems != null && formItems.size() > 0) {
                // 迭代表单数据
                for (FileItem item : formItems) {
                    // 处理不在表单中的字段
                    if (!item.isFormField()) {
                        String fileName = new File(item.getName()).getName();
                        String filePath = uploadPath + File.separator + fileName;
                        File storeFile = new File(filePath);
                        // 在控制台输出文件的上传路径
                        System.out.println(filePath);
                        // 保存文件到硬盘
                        item.write(storeFile);
                    }
                }
            }
            resp.getWriter().println("{\"msg\": \"OK\"}");
        } catch (Exception ex) {
            ex.printStackTrace();
            resp.getWriter().println("{\"msg\": \"上传失败\"}");
        }
    }

}
